221040420 has 48 divisors (see below), whose sum is σ = 626760960. Its totient is φ = 58196736.

The previous prime is 221040403. The next prime is 221040427. The reversal of 221040420 is 24040122.

221040420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 221040420.

It is not an unprimeable number, because it can be changed into a prime (221040427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18577 + ... + 28056.

It is an arithmetic number, because the mean of its divisors is an integer number (13057520).

Almost surely, 2^221040420 is an apocalyptic number.

221040420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221040420 is an abundant number, since it is smaller than the sum of its proper divisors (405720540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221040420 is a wasteful number, since it uses less digits than its factorization.

221040420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46724 (or 46722 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 221040420 is about 14867.4281568804. The cubic root of 221040420 is about 604.6312166364.

Adding to 221040420 its reverse (24040122), we get a palindrome (245080542).

The spelling of 221040420 in words is "two hundred twenty-one million, forty thousand, four hundred twenty".